M1921 Browning machine gun

The M1921 was a water cooled .50 caliber heavy machine gun designed by John Moses Browning, who began development in 1917 by scaling up his .30 caliber M1917 design to chamber the larger round, producing a prototype tested in 1918. It entered limited service with the United States Army and Navy in the late 1920s before being superseded by the improved M2 Browning in 1933. The M1921A1 variant introduced in 1930 weighed 79 pounds without water, measured 56 inches long with a 36 inch barrel, and fired at a rate of 500 to 650 rounds per minute. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/